Freshwater Microbial Ecology

Freshwater microbial ecology is shaped by the availability of organic carbon, nutrients, oxygen, and light.

Near the surface, phytoplankton use sunlight to convert carbon dioxide into organic carbon.

In shallow waters, diatoms contribute to organic carbon production, while heterotrophic microbes break down this organic carbon, releasing carbon dioxide and recycling nutrients back into the water.

Biofilms on submerged surfaces trap organic matter from the water, where bacteria, fungi, and protists work together to break it down and release carbon dioxide.

The benthic zones typically receive carbon from leaf litter and submerged organic matter, which is degraded by heterotrophic microbes.

These microbes release dissolved organic carbon back into the water, supporting nearby microbial communities.

Urban and agricultural runoff can introduce organic waste into freshwater, leading to eutrophication.

This promotes cyanobacterial blooms on the surface and subsequent oxygen depletion as heterotrophic microbes decompose excess biomass, affecting the overall structure of the microbial community.